Skin and pulp of figs and fig extracts (Antico et al. 2003) [874]. Extracts were prepared by separating the skin from the pulp and extracting them separately with PBS (1:4, w:v) for 15 min at 4°C. After centrifugation at 12 ooo g for 15 min at 4°C, the supernatants were collected and stored at -20°C.

Protocol: (controls, definition of positive etc)

Prick-to-prick method. Reactions were judged as ++ if the weal diameter exceeded 3 mm, and as +++ if equivalent to or greater than the positive control (histamine dihydrochloride 10 mg/mL). Weals between 2 and 3 mm with surrounding erythema were classified as weakly positive (+) (Focke et al. 2003).

Five patients reporting adverse reactions after the ingestion of figs. A sixth patient, who never ever ate figs, was included because she reported respiratory symptoms from contact with ornamental FB (Ficus benjamina) trees (Focke et al. 2003).

Three patients with clincal history of pollinosis and symptoms after ingestion of figs (Caiaffa et al. 2003)

Two patients with symptoms after ingestion of fig fruis (Antico et al. 2003)

Summary of Results:

SPT was 1+ in 1 patient and 3+++ in two other patients. Testing with possibly associated fruits (mulberry, banana, avocado, kiwi fruit) and latex revealed weakly positive reactions to banana, avocado and kiwi fruit in some cases. No patient reacted with latex. (Hemmer et al. 1998)

Prick to prick tests carried out with the skin fraction gave a stronger positive response than with the pulp fractions. These results were confirmed by pricking the extracts of both fig skin and pulp (Antico et al. 2003)

Specific IgE was positive for both fig fruit and Ficus benjamina (FB) latex. PAST was completly inhibited by preincubation of serum with FB. However, the specific IgE binding to FB was only partially (50-55%) inhibited by preincubation of serum with fig extract. Immunoblot-inhibition also showed cross-reactivity between FB and fig but not to birch, mugwort and phleum pollens or Bet v 2 (Mock et al. 1998)

RAST to fig fruit was positive in all patients (1.68/4.98/1.39 kU/l) as was RAST to Ficus sp. (CAP K81) (5.31/60.8/1.22 kU/l). All patients were also sensitized to pollen allergens (Hemmer et al. 1999).

No IgE to fig was detected for any of the patients (Antico et al. 2003). IgE immunoblotting showed recognition of a major band of 20 kDa by one patient and three bands of 10, 22 and 24kDa by the other patient.

Specif IgE to fig extract was found in the patients's serum (Dechamp et al. 1995)

A major band of 20 kda plus a minor band with a lower molecular weight were recognised in the skin extract by patient no. 1, while 3 bands (10,22 and 24 kda) weere detected by patient no. 2. No IgE-binding bands were found in PBS-soluble fraction of of the fig pulp. However, 2 bands were recognised by patient no. 1 in the PBS-insoluble fraction of the pulp (Antico et al. 2002).

The extract contained two allergens of 19 and 35 kda recognised by the patient (Gandolfo et al. 2001) [829].

Under non-reducing conditions no IgE bands were detected. Under reducing conditions strong IgE binding to high molecular weight allergens (30-70 kda) were seen in only one patient (Hemmer et al. 1999)

Only two patients were positive in the fig fruit blots. Patient 3 reacted moderately with a protein smear between 40 and 100 kDa and a 20 kDa band. Patient 6 reacted with allergens between 30 and 100 kDa, with two poorly delineated bands near 45 and 55 kDa. RAST to FB (Ficus benjamina) was inhibited >95% by FB extracts and 16-65% (mean 49%) by extracts from fresh fig. RAST to fig fruit was inhibited >95% by FB and fresh fig, 63-97% (mean 86%) by dried fig, and 0-84% (mean 35.5%) by kiwi fruit (Focke et al. 2003).

Oral provocation

Number of Studies:1-5

Food used and oral provocation vehicle:About 20 g of a green fig were chewed for 1 min and spat out (Antico et al. 2003)

Blind:Open

Number of Patients:

Two patients with symptoms after ingestion of fig fruis (Antico et al. 2003)

IgE cross-reactivity and Polysensitisation

Cross-reactivity between fig and mulberry has been observed by Caiaffa et al. 2003

Gandolfo et al. (2001) [829] and Focke et al. 2003 concluded that Allergic reactions to fresh or dried figs can present as a consequence of primary sensitization to airborne Ficus benjamina allergens independent of sensitization to rubber latex allergens. Kiwi fruit, papaya, and avocado as well as pineapple and banana may be other fruits associated with sensitization to Ficus allergens.